3.0L Diesel Dyno

[mtnmerlin]

For funzies, I thought I would post the 3.0L vs 3.6L comparison graph.

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[rogo]

This chart makes me really want to consider getting rid of my '18 3.6.

For funzies, I thought I would post the 3.0L vs 3.6L comparison graph.

 

[rubileon]

For funzies, I thought I would post the 3.0L vs 3.6L comparison graph.

This chart makes me really want to consider getting rid of my '18 3.6.

What you feel in power and torque is relative. Look at the super narrow torque band in the diesel. It goes down starting before 3000 rpm and you would feel that in a bad way.

To look at it another way, in the diesel, the torque will only feel good during 62.5% of the RPM band. In the Pentastar it's fun for 75%. That's what you feel when driving... not the numbers measured on a dyno. Plus there's the smoothness and the near orchestral soundtrack of the Pentastar all the way to 6500 RPM that neither the diesels or the I4 has. Diesel? No thanks.

 

[mtnmerlin]

What you feel in power and torque is relative. Look at the super narrow torque band in the diesel. It goes down starting before 3000 rpm and you would feel that in a bad way.

To look at it another way, in the diesel, the torque will only feel good during 62.5% of the RPM band. In the Pentastar it's fun for 75%. That's what you feel when driving... not the numbers measured on a dyno. Plus there's the smoothness and the near orchestral soundtrack of the Pentastar all the way to 6500 RPM that neither the diesels or the I4 has. Diesel? No thanks.

Your analysis is flawed. The reason the diesel torque curve looks "super narrow" in that chart is because the gasoline engine needs high RPM to develop power by comparison. Look at the vertical difference in the curves. The 3.0L diesel needs 3000 RPM to develop 250HP and the 3.6L needs 5000 RPM to develop 250HP which is a huge advantage for the diesel. More importantly, in the range where you do 99.99% of our driving (1500 RPM to 2000 RPM) the diesel has much higher horsepower. At 1800 RPM you will be cruising at 75MPH. Do you want 155HP or 70HP at that speed?

 

[BuffaloBill]

What you feel in power and torque is relative. Look at the super narrow torque band in the diesel. It goes down starting before 3000 rpm and you would feel that in a bad way.

To look at it another way, in the diesel, the torque will only feel good during 62.5% of the RPM band. In the Pentastar it's fun for 75%. That's what you feel when driving... not the numbers measured on a dyno. Plus there's the smoothness and the near orchestral soundtrack of the Pentastar all the way to 6500 RPM that neither the diesels or the I4 has. Diesel? No thanks.

Another variable of course, is the transmission. It’s the transmission’s job to make good use of the engine’s output. If done well, the relatively narrow rpm band of the diesel is no problem; it’s actually more satisfying (to me) to hear/feel the rapid up-shifts.

I own an 18 JK Rubicon with the Pentastar and a 14 Ram 1500 EcoDiesel. Granted, the Jeep would certainly benefit by the 8-speed. I’ve not driven one with the 8speed & Pentastar but have ridden on occasion in GC with that combination. I imagine the 8speed on the Pentastar would make less annoying it’s lack of torque (relative to the diesel I mean). The GC I referred to did seem to downshift quite easily with headwinds or inclines. One viewpoint on that is “that’s what the transmission is for”. That does make technical sense but it bugs me!

I can say that the transmission in the Ram does a good job with the gen2 Ecodiesel, and hope the new JL will be similar in that regard. On acceleration it rows through the gears and once there, will hold that gear into mild wind or incline.

Both are fun to drive but I find the powertrain of the Ram to be more satisfying.

 

[JMatt]

What you feel in power and torque is relative. Look at the super narrow torque band in the diesel. It goes down starting before 3000 rpm and you would feel that in a bad way.

To look at it another way, in the diesel, the torque will only feel good during 62.5% of the RPM band. In the Pentastar it's fun for 75%. That's what you feel when driving... not the numbers measured on a dyno. Plus there's the smoothness and the near orchestral soundtrack of the Pentastar all the way to 6500 RPM that neither the diesels or the I4 has. Diesel? No thanks.

This entire postis just factually wrong in virtually every way. I'll just clarify one of the points: With the 8 speed auto, you can shift the diesel at 2,800 rpm and it drops to roughly 1,800 rpm (each shift is slightly different, but roughly within 100 rpm of that). So from 0-100 mph you will be at peak torque the entire time. With more torque and more horsepower available than the V6 100% of the time. So if by "fun" you mean fun like riding a moped instead of a motorcycle, then yes, a moped can be fun too.

Now, let's talk about tuners with a transmission rated for 750 lbs ft . . .

 

[rubileon]

The reason the diesel torque curve looks "super narrow" in that chart is because the gasoline engine needs high RPM to develop power by comparison.

No. Do the math... the diesel's torque goes down during 37.5% of the RPM window and it becomes almost 50%. In the Pentastar, it goes down during 25% of the RPM window, which is not as bad and it only goes down by about 15% which is heaps better in terms of how it feels.

Another variable of course, is the transmission. It’s the transmission’s job to make good use of the engine’s output. If done well, the relatively narrow rpm band of the diesel is no problem; it’s actually more satisfying (to me) to hear/feel the rapid up-shifts.

The transmission becomes a factor in what I said under light/moderate throttle where it can...

... through the ratios while keeping the RPM in the most efficient range but if you ever floor it, you'd feel the loss of torque quicker and more rapidly. Please also see my reply to mtnmerlin above for the numbers.

With more torque and more horsepower available than the V6 100% of the time.

No. What you feel aren't the absolute numbers. That was the original point. For example, gokarts have single digit horsepower numbers and horrendous power to weight ratios compared to even Wranglers and by your logic, they shouldn't be fun to drive at all.

Please see my reply to mtnmerlin in this post for the numbers and my reply to BuffaloBill about when the transmission cannot solve the torque drop in the diesel.

 

[BuffaloBill]

Not all Jeepers in Australia dress like that, do they?

 

[Compression-Ignition]

What you feel in power and torque is relative. Look at the super narrow torque band in the diesel. It goes down starting before 3000 rpm and you would feel that in a bad way.

To look at it another way, in the diesel, the torque will only feel good during 62.5% of the RPM band. In the Pentastar it's fun for 75%. That's what you feel when driving... not the numbers measured on a dyno. Plus there's the smoothness and the near orchestral soundtrack of the Pentastar all the way to 6500 RPM that neither the diesels or the I4 has. Diesel? No thanks.

No. Do the math... the diesel's torque goes down during 37.5% of the RPM window and it becomes almost 50%. In the Pentastar, it goes down during 25% of the RPM window, which is not as bad and it only goes down by about 15% which is heaps better in terms of how it feels.


The transmission becomes a factor in what I said under light/moderate throttle where it can...

... through the ratios while keeping the RPM in the most efficient range but if you ever floor it, you'd feel the loss of torque quicker and more rapidly. Please also see my reply to mtnmerlin above for the numbers.




No. What you feel aren't the absolute numbers. That was the original point. For example, gokarts have single digit horsepower numbers and horrendous power to weight ratios compared to even Wranglers and by your logic, they shouldn't be fun to drive at all.

Please see my reply to mtnmerlin in this post for the numbers and my reply to BuffaloBill about when the transmission cannot solve the torque drop in the diesel.

An underpowered kart is going to be way more fun for the 100lb kid than the 200lb adult. Given 2 cars with similar horsepower yet one has quite a bit more torque I'll take the extra torque all day long.

Hate whatever you want, just try to make valid points in doing so......

I don't much care for leftists. But just because a good looking woman is a batshit crazy death cultist loon doesn't mean I'll try to tell you she's ugly.

You think diesel is killing the earth and everyone on it right? Fair enough. But acting like it is the poorest choice in fuel is asinine. What fuel motivates most mobile equipment around the globe? Why is that?

 

[JMatt]

No. What you feel aren't the absolute numbers. That was the original point. For example, gokarts have single digit horsepower numbers and horrendous power to weight ratios compared to even Wranglers and by your logic, they shouldn't be fun to drive at all.

Please see my reply to mtnmerlin in this post for the numbers and my reply to BuffaloBill about when the transmission cannot solve the torque drop in the diesel.

You have zero idea what you're talking about. I've raced everything from shifter karts (which have awesome power to weight ratios by the way), to Porsche 911s, to my ultimate ride - a 2,100hp blown alcohol dragster. I'm pretty confident I understand hp, torque, gear ratios, and power to weight ratios. You clearly need some time in a performance related classroom.

 

[rubileon]

An underpowered kart is going to be way more fun for the 100lb kid than the 200lb adult. Given 2 cars with similar horsepower yet one has quite a bit more torque I'll take the extra torque all day long.

Hate whatever you want, just try to make valid points in doing so......

I don't much care for leftists. But just because a good looking woman is a batshit crazy death cultist loon doesn't mean I'll try to tell you she's ugly.

You think diesel is killing the earth and everyone on it right? Fair enough. But acting like it is the poorest choice in fuel is asinine. What fuel motivates most mobile equipment around the globe? Why is that?

Prejudiced much? No one buys a Wrangler because they're a tree hugger. And this is not a comment on all diesels because clearly this engine is not the best that diesels have to offer. If you want to blame anyone because you can't explain, blame FCA for making the torque go flaccid (becoming almost half!) during the last 37.5% or so of the RPM range.

 

[rubileon]

You have zero idea what you're talking about. I've raced everything from shifter karts (which have awesome power to weight ratios by the way), to Porsche 911s, to my ultimate ride - a 2,100hp blown alcohol dragster. I'm pretty confident I understand hp, torque, gear ratios, and power to weight ratios. You clearly need some time in a performance related classroom.

So the sole reason why no one should not believe their eyes and brain is because you said so? What you have mentioned has nothing to do with this concept. And here's more news... butt dyno is real and defies what you have supposedly learned.

 

[JMatt]

So the sole reason why no one should not believe their eyes and brain is because you said so? What you have mentioned has nothing to do with this concept. And here's more news... butt dyno is real and defies what you have supposedly learned.

Well, you already disregarded the actual dyno, which puts the diesel at higher torque AND higher hp than the V6 from 0-100 mph while the transmission does its job keeping the engine in its power band. So you don't understand or believe 1) the math, 2) the science, and now 3) people with actual experience. I think you've cemented your status here well. Congrats on that.

 

[GtX]

Now, let's talk about tuners with a transmission rated for 750 lbs ft . . .

553 lb ft, right? The 750 is Nm.

 

[rubileon]

Well, you already disregarded the actual dyno, which puts the diesel at higher torque AND higher hp than the V6 from 0-100 mph while the transmission does its job keeping the engine in its power band. So you don't understand or believe 1) the math, 2) the science, and now 3) people with actual experience. I think you've cemented your status here well. Congrats on that.

Here's what I said:

1. The diesel V6's torque drops during the last 37.5% of the RPM range by around 50%.

2. The Pentastar's torque drops during the last 25% of the RPM range and by around 15%.

These are all from the dyno chart shown. Which engine gives the worse feeling when it loses torque (remembering that this is a relative thing)? Hear the silence from everyone who's not disputing the numbers above? They know how to read a chart and they know you don't drive with one cheek on the diesel and one cheek on the Pentastar to be able to feel absolute figures. This diesel is a kill joy. Please take it up with FCA if you have a problem.

As for my status here... lol I don't look for validation or status from people on a forum, but you seem to do